This question is a related to this question which has been closed.
I will explain the whole situation here again and the question is different:
I wrote to a prof. on December 15 in Germany whose specialization aligns with mine in Pure Math and he replied back:
thanks for your interest . We can in principle discuss the possibility of a PhD with me, but I should warn you that it's unlikely to work out in the end - first of all, most likely I won't accept any new PhD students for the next year.
If you nevertheless want me to consider accepting you, please send me your Master's thesis and ask at least one of your recommenders to directly email their recommendation letter to me.
I sent him my thesis and 2 LOR's and told him that I viewed 1 talk given by him and read 3 of his research papers to become more familiar with recent techniques he is using.
To which he replied:
thanks, I've received your recommendations. First, let me repeat what I wrote to you previously - I most likely don't want to accept any new PhD student this year, so if I don't accept you, it will probably be to a large extent for that reason.
However, we could talk over zoom sometimes to discuss things. I'm quite busy at the moment, so let's do it at the end of January - can you please email me around Jan 21 telling your time availibilty on Jan 24.
Question: The prof. might tell me some of his colleagues that I can write to. But I have already written to them (by going through his papers I came to know who he has collaborated with). I really want to work under his supervision and some other professors I wanted to work with will not take any new students this year. I wrote also to 3 professors in France and they haven't replied to me despite sending a remainder mail. How can I persuade (if that is the correct word to use here, English is not my native language) him to take me without being needy?
In his 2nd reply he told me that "However, we could talk over zoom sometimes to discuss things". What exactly can we discuss in that meeting? What should I do to make the most of that meeting?
I can talk about the other place I wrote to / applied to , my master's thesis, my knowledge in the particular branch I want to work in and also other branches or the topics I am studying now.
I think it is very kind of him to give me a chance. He could have simply said no. But he is interested in giving time from his busy schedule.